PythonSLM 0.1

Python Package for Additive Manufacturing Development

PySLM is a python library for processing the input files used on Selective Laser Melting (SLM), Direct Metal Laser Sintering (DMLS) platform typically used in both academia and industry for Additive Manufacturing. The core capabilities aim to include slicing, hatching and support generation and providing an interface to the binary build file formats available for platforms. The library is built of core classes which may provide the basic functionality to generate the scan vectors used on systems and also be used as building blocks to prototype and develop new alogirthms.

PySLM is built-upon python libraries Trimesh and based on some custom modifications to the PyClipper libraries which are leveraged to provide the slicing and manipulation of polygons, such as offsetting and clipping of lines. Additional functionality will be added to provide basic capabilities.

The aims is this library provides especially for an academic environment, a useful set of tools for prototyping and used in-conjunction with simulation and analytic studies.

Current Features

PySLM is building up a core feature set aiming to provide the basic blocks for primarily generating the scan paths and additional design features used for AM systems typically (SLM/SLS/SLA) systems which consolidate material using a single/multi point exposure by generating a series of scan vectors in a region.

Support Structure Generation * [TODO] A prototype for support structure generation

Slicing:

• Slicing of triangular meshes supported via the Trimesh library.

Hatching:

• Standard ‘alternating’ hatching is available

• Stripe Scan Strategy Available

Visualisation:

• The laser scan vectors can be visualised and

Export to Machine Files:

• Currently WIP to port previous c++ code and provide generic bindings to platforms (Renishaw MTT, Realizer, EOS CLI formats)

Installation

Installation is currently supported on Windows and Linux environments. The prerequisties for using PySLM can be installed via PyPi and/or Anaconda distribution.

conda install -c conda-forge shapely, Rtree, networkx, scikit-image
pip install trimesh

Installation of pyslm can then be performed using pre-built python packages using the pypi project.

pip install pyslm

Alternatively, pyslm may be compiled from source. Currently the prerequisites are the cython packagee and a c++ build environment.

git clone https://github.com/drlukeparry/pyslm.git && cd ./pyslm
python setup.py install

Usage

A basic example below, shows how relativly straightforward it is to generate a single layer from a STL mesh which generates a the hatch infill using a Stripe Scan Strategy typically employed on some commercial systems to limit the maximum scan vector length generated in a region.

import pyslm
from pyslm import hatching as hatching

# Imports the part and sets the geometry to  an STL file (frameGuide.stl)
solidPart = pyslm.Part('myFrameGuide')
solidPart.setGeometry('../models/frameGuide.stl')

# Set te slice layer position
z = 23.

# Create a StripeHatcher object for performing any hatching operations
myHatcher = hatching.StripeHatcher()
myHatcher.stripeWidth = 5.0

# Set the base hatching parameters which are generated within Hatcher
myHatcher.hatchAngle = 10
myHatcher.volumeOffsetHatch = 0.08
myHatcher.spotCompensation = 0.06
myHatcher.numInnerContours = 2
myHatcher.numOuterContours = 1

# Slice the object
geomSlice = solidPart.getVectorSlice(z, returnCoordPaths = True)

#Perform the hatching operations
layer = myHatcher.hatch(geomSlice)

# Plot the layer geometries
hatching.Hatcher.plot(layer, plot3D=False, plotOrderLine=True) # plotArrows=True)

Documented examples are provided in examples .